S-adenosyl-l-methionine: effects on brain bioenergetic status and transverse relaxation time in healthy subjects

Background S-adenosyl-L-methionine is an effective treatment for clinical depression, although the mechanism underlying this effect is unclear. Presently, in vivo phosphorus 31 magnetic resonance spectroscopy and brain transverse relaxometry were employed to test if S-adenosyl-L-methionine supplementation alters brain bioenergetics and/or transverse relaxation time in a nondepressed cohort. If these magnetic resonance techniques are sensitive to S-adenosyl-L-methionine induced alterations in neurochemical processes, these methods may be used in cases of clinical depression to elucidate the mechanism underlying the antidepressant effect of S-adenosyl-L-methionine. Methods Twelve subjects self-administered 1600 mg of oral S-adenosyl-L-methionine daily. Phosphorus 31 spectra and transverse relaxation time were acquired at baseline and after treatment using a 1.5 Tesla scanner. Results Mole percent concentrations of phosphocreatine were significantly higher after treatment, whereas mole percent β nucleoside triphosphate levels, predominantly adenosine triphosphate in brain, were significantly lower after treatment. In addition, a surprising gender difference in transverse relaxation time emerged after supplementation, with women exhibiting significantly lower transverse relaxation time than men. Conclusions The alterations in phosphocreatine and β nucleoside triphosphate are consistent with the report that S-adenosyl-L-methionine is involved in the production of creatine, which in turn is phosphorylated to phosphocreatine using adenosine triphosphate. These findings suggest that S-adenosyl-L-methionine alters parameters associated with cerebral bioenergetic status and that some effects of S-adenosyl-L-methionine (transverse relaxation time) occur in a gender-specific manner.